Free-chain hoist



F. W. COFFING FREE CHAIN HOIST Nov. 23, 1937.

Filed Nov. 30, 1934 2 Sheets-Sheet l IIS @f ,/v ==E= /f I INVENTOR. fkfa/cx /44 [kfw/va Ww Pg?.

ATTORNEY `lov. 23, 1937. F. w. coFFlNG 2,099,676

FREE CHAIN HoIsT Filed Nov. 30, 1934 2 Sheets-Sheet 2 Pl. B

ATTORNEY.

Patented Nov. 23,' 1937 UNITED STATES PATENT OFFICE 15 Claims.

This invention relates to a free-chain hoist. By free-chain hoist is meant a hoist which is capable of having the load supporting chain rapidly positioned to an approximate position for associating the load therewith as distinguished from a chain hoist wherein the load supporting chain must, through the operation of the device, be positioned relative to a load by performing the reverse operation for lowering the chain to the desired position for load engagement, as is required to raise it for elevating the load.

This invention is a continuation in part of that shown in the copendirig application, entitled, Free-chain hoist, Serial No. 736,280, led July 21, 1934, and allowed October 11, 1934, and now Patent No, 1,999,036, dated April 23, 1935, and like the latter which was directed to the addition and modification of a free-chain hoist, so as to incorporate foolproof provisions, this invention o is directed to additional foolproof provisions over the inventions disclosed in the before mentioned copending application and Patent No. 1,973,844, dated September 18, 1934, which, as an application, was copending with the before mentioned 05 copending application;

yThe foolproof provisions in the present instances are directed principally to the following phases: The maintenance of the control member in one of its extreme positions and coupled there- -with the prevention of the movement of the control member into the aforesaid position accidentally by too strenuous actuation thereof.

A second foolproof provision consists in the addition of a speed control arrangement which automatically prevents the rotation of certain of the parts faster than a predetermined speed when rotating in what may be termed the lowering direction.

Another foolproof provision is the formation of the casing or housing of the hoist such that the endless element associated with the manual power or hand wheel is guided to the wheel and is guided from the wheel and is retained by the guiding means to prevent fouling of the endless element with respect to the wheel, particularly in quick starting or quick stopping.

An `additional improvement consists in providing a cushion type anchor for the end of the load elevating chain so that in the event the chain runs out in lowering the load, there will be obtained a cushioning action before the chain is fully exhausted. This prevents shearing of the chain mounting, resulting from a quick fast dropping and complete exhaustion of the chain which may occur in the forms of the ,invention shown in the copending application and patent before mentioned.

The present inventionalso embodies the foolproof provisions shown in the copending application, together with all the other improvements 5 found in said copending application over the structure illustrated in the before mentioned patent.

The full nature of the invention will be fully understood from the accompanying drawings and 10 the following description and claims:

In the drawings, Fig. 1 is a side elevational view of one embodiment of one invention broadly disclosed in the copending application and patent before mentioned,the cover being removed and 15 a part of the chain moving gear being broken away to illustrate certain of the parts in greater detail.

Fig. 2 is a sectional view through the hoist shown in Fig. l, certain parts of the invention, 20

however, being shown in elevation and the speed control being more specifically illustrated.

Fig. 3 is a view similar to Fig. l but of a lesser amount of the mechanism, with the parts illustrated in the full release position, 'wherein the 25 brake structure is fully released and there is complete disengagement of the intermeshlng gears, the chain cushioning anchorage being shown in the cushioning position with the exhaustion of the chain and the control being 30 shown locked in the fully released position.

Fig. 4 is a side elevational view of the combination shifting mechanism, shown more particularly in Figs. 1 and 3.

Fig. 5 is a bottom plan view taken approxi- 35 mately on line 5 5 of Fig. 3 and in the direction of the arrows.

Fig. 6 is a side elevational view of the hand power wheel with a portion of the centrifugally operable speed control mechanism incorporated 40 therewith.

Fig. 7 is a side elevational view of a modified form of hoist embodying all the features of the invention shown in Figs. l to 6, inclusive, with `the addition of the wheel chain guide mechanism 45 provided witha cutout portion II which provides yboth an entrance and exit for a sprocket chain I8. 'I'he cover is provided with an anchorage I1 to which the hoisting end of the chain is preferably permanently secured in any suitable manner when a loop is desired to increase the capacity ef the hoist in the well known manner, to

1 and 3-the load adjusting end |8 o1' the chain is connected to one arm |09 of a lever pivotally supported at |00 upon the cover. The other arm |01 of the lever is connected to one end of a tension spring |08, the other end of which is connected to an adjusting member |05 that passes through an apertured boss |04 on the cover and the tension of the spring is adjusted thereby and maintained in adjustment by the nuts |03. The member |00 may consist of an eye bolt.

As shown clearly by a comparison of Figs. 1 andS, when the chain is fully extended in the load lowering position by movement of the chain from the position shown in Fig. 1 to the position shown in Fig. 3, substantially at the end of the exhaustion of the chain, continued movement of the latter tilts the lever |01|03 upon its pivot |08 and this movement is opposed by the tension spring |00. In other words, upon exhaustion of the chain, instead of as illustrated in the before mentioned patent and application, the chain dead-ending at a fixed anchorage, the` chain in the present instance can continue to pay out a slight amount additional, which movement is opposed by the spring |08 so a cushioning stop action results and which prevents the possibility of shearing of the chain from its anchorage, if only a fixed anchorage of the chain to the hoist body (or cover) were provided.

The cover at 2|-see Fig. 2--and the housing at 22 provide anti-friction bearings |2| and |22,

respectively, for a shaft 23 which mounts a' sprocket 2l that may, if desired. be formed integral with said shaft. Suitably and rigidly secured to the shaft is a gear 25.

The cover is provided with a bearing 28 and the housing is provided with a bearing 21, the latter being closed and the former consisting of an opening through the cover. Mounted in these bearings are the antifriction constructions 28 and 23, respectively. l

Rotatably supported by said anti-friction constructions. is a shaft 30, one end of which is fully enclosed by the housing and the other end 3| of which projects beyond the hoist and herein the cover portion, and is provided with suitable power means for rotating the shaft in either direction. Herein the exposed end 3| of shaft 30 is shown provided with a wheel 32 rigidly secured to said shaft and the same carries an endless chain 33 of the transverse link type.

A chain guard 9-see Figs. 1 to 3 inclusiveis interposed between the load chain sprocket 24 and the shaft 30-3I.

A suitable guide, or retainer, in the form of a -Ushaped bracket 34 extends from the cover with whichit is integral, envelopes the wheel 32 and serves to prevent escapement of the chain 33 from the wheel. Any suitable means for securing the lwheel 32 to the shaft may be provided. the same not being shown herein. The shaft 3l includes a shoulder |38 against which bears one end of the bearing 28 -against which in turn may bear one end of a spring 38 concentric with the shaft and telescopically mounted upon a tubular extension 31 of a pinion 38 that is slidably mounted on said shaft. In the forms of the inventionl wherein positive pinion engaging and disengaging means is employed, the spring may be, and preferably is, omitted. Plate 35 retains the assembly in proper relation. Pinion 38 is adapted to be rotated by said shaft through suitable means, such as a. spline connection 39.' The pinion 38 normally meshes with the gear 25 but is removable therefrom.

In place of the hand wheel 32 and chain 33 there may be provided any suitable source of power, such as a unidirectional motor and in certain forms of the invention, the wheel 32 may have an internal gear with which is associated a pinion driven by an electric motor of unidirectional character and in this latter modified form of the invention, either electric or hand power may be employed as desired, but it is to be understood that the application of external power to shaft 3| is of a unidirectional character for elevating, although the shaft has reverse movement for load lowering under the weight of the load or reverse movement for free chain positioning when removed from the load.

In load lowering, the endless hand chain 33 -and the wheel 32 act as an additional load which prevents quick starting movement in the initial lowering movement of the load, because the initial eflect of gravity on the load must overcome the inertia of the wheel and chain in its resistance to turning in a reverse direction from that it has previously turned in load elevating or overcome the inertia in starting the hand wheel and chain to move in said reverse direction.

In load lowering, to prevent excessive speed,an automatic governor may be provided-see Figs. 2 and 6. The cove'r is provided with an extension III having a cylindrical bore IIII. Extension projects into and nests within the chain engaging flange of wheel 32 adjacent the cover. The Vwheel 32 pivotally supports a plurality of weighted levers, one end of each of which is attached to a segmental brake shoe adjustably anchored at its opposite end to the wheel.

Herein but two oppositely positioned similar structures are illustrated which provide for better balance. The additional weight thereof, due to inertia thereof, also serves as a further element for cushioning a quick start in load lowering.

Each weighted lever ||2 is pivoted at ||3 to the wheel and includes the weighted end III. A lug ||5 is pivotally connected to one end of an internal band or shoe ||6 anchored at ||1 to the wheel. Each shoe may be provided with a suitable surfacing, such as brake lining I8 or the like.

For speed regulation adjustment, one end of a spring ||9 is associated with lever ||2. The other end is secured to an arm |20 carried by a shaft 2| which extends through the wheel 32. The exposed end of the shaft |2| mounts adjusting and lock nuts |22 to secure shaft |2| in rotatablyY adjusted position for suitable adjustment of the force of the spring H3. The spring normally tends to oppose outward movement of its associated weighted lever 2 due to centrifugal force. When the force of the spring is overcome, additional rotation (that is, increased speed of shaft 3|) tilts lever ||2 to force the shoe ||8 into engagement with cylinder or drum Ill. This tends to retard the increased rotation or speed. Also the greater the tendency toward overspeed, the greater will be the restraining relation exerted by the cylinder and shoes cooperating together.

Overspeeding in load lowering, with the possible result of subsequent failure of some other part ofthe hoist mechanism is prevented. This device also prevents deposition of the load with a force suiiicient to damage or destroy the load even if the hoist were to fail.

For load raising movement, this speed control mechanism is not effective. Also, it isF usually adjusted so that it becomes eiective just prior to the exhaustion of the brake capacity hereafter to be set forth more fully.

When the shaft 3| is-rotated, the sprocket will be rotated in a corresponding direction for load elevation or load lowering, if the pinion 38 is in meshing engagement with the gear' 25. If the pinion is not engaged with the gear, then the chain a, or other power means, is not effective for obtaining sprocket movement no matter how much shaft 3| is rotated.

By reason of the possibility of disassociating the pinion and gear in one form of the invention, means must be provided for holding the sprocket corresponding to the desired position the load is to be held in to permit working on the load.

Such means, herein, includes a brake drum 4|l see Fig. l-and a brake band 42 which has one end (extension 4,3) adjustably anchored to the housing as hereafter set forth and which has its other end pivoted to the housing at 6|.

The end 43 of band42 is connected to one end of a coil spring 45, the opposite end of which is connected to an arm 46 pivotally mounted as at 41 in an opening in a housing ||l. The exposed end of the member 41 is provided with a suitable means 48, whereby from without the housing the rotative position of the arm 46 may be clampingly associated with the housing to determine the adjusted position of said arm 46. When the arm is positioned as shown in Fig. l, the coil spring is under what may be termed normal tension and the brake band is in the drum engaging position.

When the arm 46 is rotated into a lower position, an additional tension will be imposed by coil spring 45, upon the band 42 normally band 42 is always constrained by spring 45 into drum engagement. The band, if desired, may be provided with a facing or lining 49. 'I'his brake structure is adapted to hold the sprocket and load in the desired elevated position.

The housing I0 at 26 is provided with threaded apertures and adjustable stops in the form of 7oolts 44 are mounted therein and locked in the adjustable position by the lock nuts 44a. in Fig. 1 the ends of the bolts do not contact the brake band, whereas, where the brake parts are shown in Fig. 3, the released position, the brake band will be in contact with said adjustable stops.

inasmuch as the brake is normally constrained toward braking operation at all times, as distinguished from the speed control device which is normally ineffective for braking in either direction, it will be apparent that it is highly desirable that the brake structure in the load elevating movement, be relatively inoperative, and to accomplish this purpose there is provided an overrunning clutch in the form of a ratchet 56 which is suitably secured to the shaft 38 as at 5| and the teeth 52 thereof are engaged by a plurality of diametrically positioned dogs 53 normally urged into ratchet engagement by springs 54 supported as at 56 upon the brake drum structure. The dogs 53 are pivotally supported as at 55 upon the brake drum structure.

With this type of construction, the brake drum, it will be apparent-see Fig. 2-is normally stationary and shaft 30 is freely rotatable in the drum for load elevation. Thus, as shaft 30 is rotated to actuate the two meshing gears to turn the sprocket 24 to elevate the load, the ratchet revolves clockwise in Fig. 1 and the pawls or dogs 53 ride over the teeth of the ratchet. When the rotational movement is discontinued, the dogs engage the immediately adjacent teeth to operatively connect the brake drum to the shaft 30 which through the pinion 38 serves to lock the sprocket wheel 24 in that position so that the load will be held 'elevated by the brake until such time as the force of spring is opposed.

The means for releasing the brake to the desired degree, to permit the load to be lowered at the desired rate below that set by the speed control, consists of a lever 60 pivoted at 6| to the housing. 'I'his pivotv 6| also constitutes the anchorage for the fixed end of the brake band 42. Lever 60 has one end or arm 62 engaged with the end 43 of the brake band 42 which is slotted for that purpose. The opposite end of the lever 60 is provided with a link 64 that connects the same to another lever 64a pivotally supported at 64b on the housing. The lever 64a is connected to a control cable 69 by a hook 65, on the end of a rod 66 that terminates in an eye 68 at the opposite end. Rod 66 is slidably supported in the opening 61 in the housing l0. v

When cable 68 is pulled downwardly, in its initial downward movement lever 64a is tilted counterclockwise and the same through the link 64 tilts clockwise lever 66 on its pivot 6| which, through the end 62 forces the brake band 42 upwardly toward stop engagement in opposition to the downward tendency imposed by spring 45. This upward movement of the brake band serves to release the drum from band engagement, thereby permitting the drum together with the shaft, meshing gears and the sprocket to reversely rotate to permit lowering of the load due to the weight of the load. 'I'he rate of lowering may be determined by the position of cable 68 or in other words, the amount of tilting movement imparted thereby to the lever 60. Overspeeding in lowering due to brake failure is prevented by the governor mechanism rst mentioned.

The rod 66 includes a stop member 966 which limits normally the amount of lowering movement of member 66 to secure brake release. Stop member |66 then engages the inner wall of housing l0. This intermediate position is not illustrated.

The rod 66 extends through opening |61 in the housing l0. This hole is of keyhole type--see Fig. 5-the enlarged portion |61a permitting passage of stop |66 through the opening, if and when desired. To prevent accidental returnof stop |66 through opening |61, the catch lug portion |68 is provided-see Figs. 1, 3, and 5. When the stop is in the position illustrated in Figs. 3 and 5, the brake 42 is fully released and other control member is in another operative position for free-chain movement.

The construction so far described, is not of a free-chain character. The advantages of a freechain hoist are too numerous to mention, but

have been suggested hereinbefore. Brieily, a socalled free-chain hoist permits the rapid positioning oi.' the chain in a positionadjacent to the load for connection to the load and with a relative freedom of movement, as distinguished from the progressive movement of the chain when under load during the lowering and/or the raising thereof.

The means herein provided for free-chain action consists in a means for removing the pinion from meshing engagement with the gear. It is perfectly evident, however, that when this type of disconnection is provided in the source of power applied to the sprocket, and inasmuch as the brake construction also is effective on the sprocket only through said meshing engagement. it will be evident that some means must be provided to prevent disengagement of4 the gears until the weight of the load has been taken oil.' the sprocket chain.

'I'he means for securing non-meshing engagement of the pinion 33 to the gear 25 includes a yoke member having arms 10 that straddle the shaft 30 and ride in an annular groove 13a in the tubular extension |33 of the pinion 33 and directed oppositely from the extension 31 thereof.

It will be recalled that in one form of the invention, spring 33 normally urges gear 33 into meshing engagement and normally maintains the same in meshing engagement. When spring 33 is not utilized, spring 35 through lever 33, pin 35 and link 33, actuates lever 1| to insure pinion and gear meshing and to maintain said engagement. When spring 33 is utilized therewith, it is merely cumulative in its action and The yoke member 1| through the arms 13 and groove 10a is adapted to disengage the pinion 33 from gear 25 in opposition to the spring 33 when the member 1| is actuated.v Member 1| is pivotally supported at 12 on a bracket 13 secured to the housing, as at 14. Lever 1|, therefore, constitutes a yoke shifter. The other end of the member 1| at 15 has a ball and socket or universal connection with one arm 13 of a bell crank lever, pivoted at 11 to the housing. Herein pivot 11 is coaxial with the bracket mounting 14. The other arm 13 is connected to one end of a spring 30, said spring at its opposite end being associated with a hook 3| that has an eye portion Bla that encircles the rod 33.

The arm 13 of the bell crank lever-see Fig. 3-is also connected, and herein said connection coincides with that of a spring 30, to a link or strap 33 which has an elongated slot 32 therein and at its lower end. A pin 35, carried by lever 6|), rides in said slot.

The pinion and gear in this form of the invention, are of spiral character. The angle or pitch of Ithe spiraling may be approximately from 6 to 12.

'Ihe connection between the yoke shifter 1| and the rod 33 and/or the employment of spiral gears in place of spur gears and the adjustable stops 44 for limiting the position of the brake band when released, constitute broadly the departures from the disclosure of the patent herein before mentioned.

The purpose of the stops N is to limit the released position of the brake and, therefore, insure its readiness for operation when desired.

If the speed control is omitted, the stops may be adjusted to insure partial dragging between the drum and band. This, to a certain extent, will prevent overspeeding in the lowering of the load. Such use of the stops, however, is not good practice, but should be used merely as a tempoit is not necessary.

rary expedient for overspeedcontrol when it is necessary to secure replacement speed control parts and the hoist is required for constant use.

The connection between the yoke shifter 1| and the control rod 33 is of dual character and is for dual purposes. 'I'he slotted link and pin conl nection 32-33-35 is to insure positive engagement of the pinion and gear so that the same are in meshing engagement for load elevation. The spring and hook connection 3|3|a83 between the bell crank lever and the rod 33 is for the purpose of securing the disengagement of the pinion from the gear but only upon the actuation of the control rod 33 beyond that necessary to secure load lowering or partial release of the brake.

The latter position, as stated, is not illustrated but brake control of the load lowering is substantially exhausted when stop |33 engages the interior of housing III. To secure full brake release and gear andpinion disengagement, stop |33 must be positioned as illustrated in Figs. 3 and 5.

Continued movement of the control rod laterally downwardly and then laterally to position stop |66 below catch lug |33, after the load has been deposited in lowered position, insures full release of the brake band from the drum. This continued movement'of the rod 33 downwardly from the brake release position secures. actuation of the yoke shifter 1| to secure the disengagement of the pinion from the gear to permit free-chain positioning in the lowering direction, as broadly disclosed in the before mentioned patent. Folowing free-chain positioning, control rod 33 is released to pass stop |33 through opening |61 and upon said release, the spring and spring 35 cooperate together with the pin 35 and the link slot 32 to secure positive meshing engagement.

The employment of spiral gears, as before mentioned, insures additional frictional contact between the gears and prevents disengagement of the pinion from the gear in the lowering of relatively light loads and is one means for insuring against dropping relatively light loads. With heavy loads, dropping due to non-meshing movement is relatively impossible, because of the weight of the load being` transmitted through the gear tooth face to the pinion` tooth face and which will hold the two in contact and prevent lateral movement of the pinion into a non-meshing position. Just the substitution of spiral gears for the spur gears, shown in the patent before mentioned, is one solution to the problem of preventing dropping of light loads in load-lowering, in the invention shown in the copending application and in said patent.

The delayed action or lost motion connection obtained through the eye 3|a and rod 33 and lever 33a insures positive disengagement only yafter the load is fully lowered or the brake band is fully released.

If and when spiral gears are employed, the lateral friction between the faces may be such that positive engagement may be quite difficult and for that reason, a positive engaging means or connection is provided and this is obtained through the slotted link and the pin connection.

By the aforesaid, it is not to be implied that the slotted link and pin connection cannot be employed with the invention vshown broadly in the before mentioned patent, but it is aflirmatively asserted that the same can be associated therewith.

i that of the speed control is desired, the cable G9 ymay be pulled until the rod 66 causes lever 64a and lever 60 to .assume a position not illustrated herein but illustrated in Fig. 3 of the copending application. This constitutes the full release position for the brake band. Under relatively light loads, this position will probably be the normal operating position.

After the load has been lowered to the desired elevation and is suitably supported, then continued pulling upon cable 69 laterally and downwardly causes stop |66 to pass through opening |61, which permits lever 64a to engage the eye 8|a of the member 8| and the same is pulled downwardly, and the brake band during this operation having been permitted to move to the full release position, remains in that position. In this movement of Athe member 8|, the spring 80 is extended and tends to tilt the' arm 18 counterclockwise-see Fig. 4-which tilts the arm 16 in'the same direction and through the universal connection 15 tilts the yoke shifter 'H to move the pinion into disengaged position in opposition to spring 36.

In this continued downward movement of the lever 50, the pin 85 cannot engage the lower end of the slot 82 in the link member 83 and positively disengage the gear until stop |66 is moved from the inside wall of housing I to pass through opening I 61. This is to insure against a single strong pull on rod 66 successively but almost in immediate succession releasing the brake and disengaging the gears. Thus, accidental dropping due to accidental gear disengagement is prevented.

When the device is to be reconditioned for load elevation, cable 69 is released by moving stop |66 from lug |68 to permit its return passage into the housing and immediately thereafter the spring d5 (as well asspring 36 if utilized) tends to tilt the yoke shifter 1| in a reverse direction by tilting lever 60 so that the pin 85 on the end of said lever engages the upper end of the slot 82 in the member 83 to tilt the bell crank lever 18-16 in a direction opposite to which it has been previously tilted to cause gear engagement. The effective constraint imposed by the spring/80 is removed. The spring 45 then also becomes operative to insure brake band engagement with the drum. lThe device is then operative for load elevation.

It will, of course, be apparent that free-chain movement corresponding to load elevating movement is possible without operating the control rod 66, because the gear 25, pinion 38, shaft-30 and ratchet 50 will all freely rotate to permit such movement. However, if the chain is heavy the sprocket and the sprocket chain need be moved.

In Figs. 7 and 8, there is illustrated a modified form of the invention which in its interior mechanism, may be of the same specic character as illustrated in the before mentioned patent and/or ,copending application as well as that described herein.

In this modification, the cover is indicated by the numeral 2|0, the handwheel by the numeral 232, the chain by 233 and the hook by 24|. v'.I'he chain guard 234 herein is of slightly diiferent form. control rod, 2|6 the load chain, 268 the stop lug, 261 and 261a the keyhole opening, 2I5 the load chain opening, and 2|2 the cover and housing connection.

Herein, an additional power chain guide casting is detachably secured to the housing as at 300. Its two diverging wings 30| and 302 terminate in outwardly flared tubular portions 303 269 indicates the control cable, 266 the and 304, respectively, and to the same and the cover 2II by brackets 305, is secured the guard 234.

Tubular portion 303 has a cross-shaped aperture 301 to permit ready passage of transversely positioned successive links of chain 233. Tubular portion 303 has a circular aperture 308 therein for ready clearance of the chain. In Fig. '1, numerals 322 indicate the speed control adjusting nuts. The aforesaid chain guide arrangement prevents fouling of the chain and chain escapement from wheel 232.

The device, therefore.' is a IIee-chainholst, capable of free-chainlmovement in 'either direction. It is fool-proof against load dropping and conditioning for load elevation, that is pinion and gear meshing, is positively assured.

The invention claimed is:-

1. In a hoist having an enclosing housing, a single clutch and brake control member, the combination of a stop rigid with said member. said enclosing housing having an aperture therein to permit longitudinal movement of the member. and an enlargement to permit passage of the stop into and out of housing, said stop upon engaging the interior wall of the housing limiting manually operable movement of the member toward clutch control position and to brake release and upon further movement of the stop through the enlargement securing clutch release, the exterior wall of said housing adjacent the enlargement and surrounding the aperture maintaining through stop engagement, said member in clutch and brake released position.

2. A device as defined by claim 1, characterized by the addition of means adjacent the housing aperture and rigid therewith preventing lateral slippage of the stop toward the enlargement preventing accidental return movement of the memb'er. A

3. In a hoist having a housing structure, a hoist operating shaft projecting therefrom, a brake structure therefor, and a power wheel for rotating the shaft in one direction for load elevation, the combination of a speed control device preventing load lowering at a rate greater than that selected including a gripping surface rigid Withthe housing, and centrifugally operable means rotatable by the shaft and cooperating with said surface, said surface including an internal drum and said centrifugally operable means including a plurality of friction segments vand a counterweighted operating member for each and hingedly connected thereto, said speed control devine being independent o: the brake structure for limiting load lowering rotation of the shaft upon brake failure or accidental brake relse.

4. Inahoisthavingahousingstructure,ahoist .operating shaft projecting therefrom, a brake structure therefor, and a power wheel foci rotating the shaft in one direction for load elevation, the combination of a speed control devicev preventing load lowering at a rate greater than that selected' including a gripping surface rigid with the housing, and centrifugally operable means rotatable by the shaft and cooperating with said surface, said surface including an internal drum and said centrifugally operable means including a plurality of friction segments and av counterweighted operating member for each, each segment being anchored at one end -and connected to a lever at its opposite end,

each lever being pivotally mounted on' said wheel and having a weighted arm constituting the counterweighted operating member, said speed control device being independent of the brake structure for limiting load lowering rotation of the shaft upon brake failure or accidental brake 5. In a hoist having a housing structure, a hoist. operating shaft projecting therefrom, a brake structure therefor, and a power wheel for rotating the shaft in one direction for load elevation, the combination of a speed control device preventing load lowering at a rate greater than that selected including a gripping surface rigid with thehouslng, centrifugally operable means rotatable by the shaft and cooperating with said surface, and yielding means for adjustably loading the centrifugallyvoperable means for initially opposing speed regulation operation, said speed control device being independent of the brake structure for limiting load lowering rotation of the shaft upon brake failure or accidental brake release.

6.Ina hoisthaving ahousing structure,a hoist operating shaft .projecting therefrom, a

brake structure therefor, and a power wheel for rotating the shaft in one direction for load elevation, the combination of a speed control device preventing load lowering at a rate greater than that selected including a gripping surface rigid so with the housing, centrifugally operable means rotatable by the shaft and cooperating with said surface, and yielding means for adjustably loading the centrifugally operable means for initially opposing speed regulation operation, said surface including an internal drum and said centrifugally operable means including a plurality of frictiony segments and a counterweighted operating member for each and hingedly connected thereto, saidI speed control device being independent of the brake structure for limiting load lowering rotation of the shaft upon brake failure or accidental brake release.

7. In a hoist having a housing structure, a hoist operating shaft projecting therefrom, a

brake structure therefor, and a power vwheel for rotating the shaft in one direction for load elevation, the combination of a speed control device preventing load lowering at a rate greater than that selected including a gripping surface rigid with the housing, centrifugally operable means rotatable by the shaft and having segments cooperating with said surface, and yielding means for adjustably loading the centrifugally operable means for initially opposing speed regulation operation, each segment being anchored at one end and connected to a lever at its opposite end. each lever being pivotally mounted on said wheel v andlhaving a weighteda'rin constituting the v counterweighted operating member, said speed control device being independent of the brake 5 structure for'limiting load lowering rotation of the shaft lupon brake failure-or accidental brake release.

8. In a hoist having a housing structurels -hoist operating shaft 'projecting therefrom, a V10 brake structure therefor, and a power wheel for rotating the shaft in one direction for loadelevation, the combination of a speed control device preventing load lowering at a rate greater than that selected including a gripping surface rigid` l5 with the housing, centrifugally operable means rotatable by the shaft and cooperating with said surface, yielding means for adjustably loading the centrifugally operable means for initially opposing speed regulation operation, and means for 2o adjusting the centrifugal opposingforce of said yielding means, said speed control device being. independent of the brake structure for limiting load lowering rotation of the shaft upon brake failure or accidental brake release. 25

9. In a hoist having a housing structme, a hoist operating shaft projecting therefrom, a brake structure therefor, and a power wheel for rotating the shaft in one direction for load elevation, the combination of a'speed control de- 30 vice preventing load lowering at a rate greater than that selected including a gripping surface rigid with'the housing, centrifugally operable means rotatable by .the shaft and cooperating with said surface, yielding means for adjustably 35 loading the centrifugally operable means for initially opposing speed regulation operation, said surface including an internal drum, said centrifugally operable means including a plurality of friction segments and a counterweighted op- 40 erating member for each and hingedly connected thereto, and means for adjusting the centrifugal opposing force of said yielding means, said speed control device being independent of the brake structure for limiting load lowering rotation of 5 the shaft upon brake failure or accidental brake release. A

l0. In a hoist having a housing structure, la. hoist operating shaft projecting therefrom, a brake structure therefor, and` a power wheel for 50 rotating the shaft in one direction for load elevation, the combination of a speed control device preventing load lowering at a rate greater than that selected including a gripping surface rigid ywith the housing, centrifugally operable 55 means including friction segments rotatable by the 'shaft and cooperating with said surface, yielding means for adjustably loading the centrifugally operable means for initially opposing speed regulation operation, each segment being ,o anchored at one end and connected to a lever at its opposite end, each lever being pivotally mounted on said wheel and having a weighted arm constituting the counter-weighted operating member, and means for adjusting the centrifugal 65 opposing force of said yielding means, said speed control device being'independent of the brake` structure for limiting load lowering rotation of the shaft upon brake failure or accidental brake release. v v 70 11. In a hoist having an enclosing housing, a load supporting chain, and a chain moving sprocket, the combination of a cushion type anchorage operatively interposed between the chain end opposite the load end and said housing 75' and enclosed within the housing for the purpose set forth.

12. In a hoist having an enclosing housing, a load supporting chain, and a chain moving sprocket, the combination of a. cushion type anchorage operatively interposed between the chain end opposite the load end and said housing, said cushion type anchorage including a lever pivotally mounted upon the housing and having one arm connected to the chain end and another arm to a spring anchored to the housing.

13. In a hoist having an enclosing housing, a load supporting chain, a chain moving sprocket, the combination of a cushion type anchorage operatively interposed between the chain end opposite the load end and said housing, said cushion type anchorage including a lever pivotally mounted upon the housing and having one arm connected to the chain end and another arm to onel end of a spring, and an adjustable spring anchorage supported by the housing and secured to the opposite end of the spring.

14. In a hoist, the combination of a load ele-y vating shaft, a housing supporting said shaft, shaft operating and controlling means -associated with said shaft, a load chain movable by the shaft, a lever pivotally mounted within the housing, and yielding means connected to one end of the lever, the opposite end ofthe lever being connected to the load chain. A

15. In a hoist, the combination of a shaft, a housing supporting said shaft, shaft operating and controlling mechanism therefor, a second shaft, a load chain sprocket in the housing and mounted on the latter shaft, a load chain for the sprocket, a chain guard within the housing interposed between the sprocket and the rst shaft, a lever pivotally mounted within the housing adjacent the sprocket, and vyielding means connected to one end of the lever, the opposite end of the lever being connected Vto one end of the load chain, said guard preventing lever and sprocket contact.

FREDRICK W. COFFING. 

